[llvm-dev] ORC error: No callback manager available

[Greg Nancarrow via llvm-dev]

Hi LLVM Developers,

I have a query about an LLVM error message that I'm encountering and I
hope it's appropriate to post to this mailing list about it.

Postgres can be built with LLVM-based JIT support.
I find that when running on Linux (RHEL8) on IBM Z hardware, using
LLVM8+, I'm seeing many instances of the following LLVM error message
appearing in the Postgres server log:

    ORC error: No callback manager available for s390x-ibm-linux

(strangely, it otherwise doesn't seem to be causing any problems)

Looking through the LLVM source code, it appears that for the
"systemz" architecture, there is  currently no local CCMgr
implementation available, and this then prevents indirection support
and COD layer support. BUT - apparently it can still function (maybe
less efficiently?) without these?
Is somebody able to clarify exactly what that error message means and
what the limitations are? Is it unwise to use LLVM on architectures on
which this error is reported?
I looked through the LLVM V10 source code and there still seems to be
this issue for systemz.

Secondly, LLVM sends this error message to standard error. As a caller
of the LLVM library, it would be nice to be able to redirect such
messages from the library - is it possible?

Hope you can advise,
Greg